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STANDARD PRODUCT
PMC-Sierra, Inc.
PM6344 EQUAD
PMC-951013
ISSUE 5
QUADRUPLE E1 FRAMER
159
When channel associated signaling (CAS) is enabled, the format of the input
BTSIG stream is selected by the DLEN bit. A logic 1 in the DLEN bit position
selects the PMC compatible format in which the BTSIG stream contains the
signaling data nibble in the lower four bits of the time slot byte. A logic 0 in
the DLEN bit position is reserved and should not be used.
GENCRC:
The GENCRC bit enables generation of the CRC multiframe when set to logic
1. When enabled, the TRAN generates the CRC multiframe alignment signal,
calculates and inserts the CRC bits, and if enabled by FEBEDIS, inserts the
FEBE indication in the spare bit positions. The CRC bits transmitted during
the first sub-multiframe (SMF) are indeterminate and should be ignored. The
CRC bits calculated during the transmission of the 'n'th SMF (SMF n) are
transmitted in the following SMF (SMF n+1). When GENCRC is set to logic 0,
the CRC generation is disabled. The CRC bits are then set to the logic value
contained in the Si[1] bit position in the International/National Bit Control
Register and bit 1 of the NFAS frames are set to the value of Si[0] bit if
enabled by INDIS, or, if not enabled by INDIS, are taken directly from
BTPCM[x]. When BTPCM[x] or Si[1] are transmitted in lieu of the calculated
CRC bits, there is no delay of one SMF (i.e., the BTPCM[x] bits received in
SMF n are transmitted in the same SMF). The same applies when
substituting Si[1] in place of the calculated CRC bits.
FDIS:
The FDIS bit value controls the generation of the framing alignment signal. A
logic 1 in the FDIS bit position disables the generation of the framing pattern
in TS0 and allows the incoming data on BTPCM[x] to pass through the TRAN
transparently. A logic 0 in FDIS
enables the generation of the framing
pattern, replacing TS0 of frames 0,2,4,6,8,10,12,14 with the frame alignment
signal, and if enabled by INDIS, replacing TS0 of frames 1,3,5,7,9,11,13,15
with the contents of the International/National Bits Control Register. When
FDIS is a logic 1, framing is globally disabled and the values in controls bits
GENCRC, FEBEDIS, INDIS, and XDIS are ignored.
Note that the above is true only if the AIS bit in the TRAN Transmit
Alarm/Diagnostic Control register is a logic 0. If AIS is logic 1, the output bit
stream becomes all ones unconditionally.
INDIS, GENCRC and FEBEDIS:
The INDIS bit controls the insertion of the International and National bits into
TS0. When INDIS is set to logic 0, the contents of the TRAN
International/National Bit Control register are inserted into TS0; when INDIS